1. Field of the Invention
The present invention relates to a circuit breaker, and particularly, to a circuit breaker having a plug interlock device for preventing a plug from being separated from a connector when a circuit breaker main body is moved from a test position to a run position or the circuit breaker is running.
2. Background of the Invention
In general, circuit breakers may be classified into a stationary type and a pull-out type. The fixed type circuit breaker merely has a breaker main body secured at a position within an electric power distributing board. The pull-out type circuit breaker has an outer case called a cradle for facilitating maintenance and repair of the breaker main body, structure of which allows push-in and pull-out of the breaker main body.
The pull-out type circuit breaker is employed in a distributing board, by which various electric devices, including the circuit breaker, all disposed therein, are managed so as to drive or control a power station, a substation and the like and to drive a motor. Also, the circuit breaker has a run position and a test position. At the run position, a power source side terminal and a load side terminal of the circuit breaker are connected to those of the cradle to thereby supply a voltage and a current, while at the test position, those terminals of the circuit breaker are separated from the terminals of the cradle so that a switching operation of the breaker main body is merely tested.
Here, in order to send an electric signal to the circuit breaker at the run position or the test position of the breaker main body to render the circuit breaker turned on or off, a device for applying power source to the breaker main body is needed. To this end, a control circuit plug is installed in the distributing board and a control circuit connector is installed in the breaker main body such that the control circuit plug is connected thereto or separated therefrom. If the breaker main body is pushed in or pulled out in a separated state between the control circuit plug and the control circuit connector or if the control circuit plug is unplugged from the control circuit connector at the run position, the circuit breaker may not run even in an emergency, which may cause an occurrence of an unexpected accident. Therefore, when the breaker main body is pushed in or pulled out or present at the run position, the circuit breaker should be managed such that the control circuit plug cannot be unplugged from the control circuit connector to obviate the risk of accident.